Circuit breaker operating mechanism



w. AQAT'WOOD ETAL CIRCUIT BREAK-ER OPERATINGMECHANISM Fil ed Feb. 23, 19:59

I nventors'. Winfield A. Atwood ph W.Seaman;

Jose V497 Z Their Attorney.

Patented Oct. 7, 1941 cmom'r BREAKEfiloPERATlNG MECHAe SM UNITED STATES PATE'VNTOFHFICE Winfield A. Atwood, Yeadori, and Joseph- W. seaman, Upper Darby, Pa. assignors to General 7 Electric Company, a corporation of NewYork Application February 23, 1939, Serial N6. 257,914

7 Claims.

Our invention relates to circuit breaker operating mechanisms, more particularly to operating mechanisms that can readily be adapted to either manual or electromagnetic, such as mo.- :tor or solenoid, operation" and has} for its principal object the provision of an improved circuit breaker operating mechanism that is symmetricalland compact withrespectto the actuating means, positive and efficient in opera.-

tion, and suitable for operation by either a manual or electromagnetic actuating unit mounted in detachable interchangeable relation thereto.

In the operation ofmoderate capacity circuit breakers, such as air circuit breakers for example, the type of actuatingmeans, such as manbreaker operating mechanisms with both manual and electromagnetic operating means. However,-in such cases the mechanism is generally completely designedfor one particular type, such as solenoid, and the manual means is added to provide auxiliary actuating means in the case of solenoid power failure In one type of mech- -anism, a solenoid is combined with the mechanism proper so as to'constitute a permanent part thereof, and the mechanismlinkage is" in addition adapted to be operated by manual crank or lever. In such cases where manual operation is preferred, the solenoid mechanism is unnecessarily expensive and inefficient. Also compactness is sacrificed unless the mechanism is completely redesigned solely for manual operation.

In accordance with our invention, the mechanism, including suitable thrust transmitting structure, is mounted in a frame or support that is adapted to receive in interchangeable detachable relation either a manual or electromagnetic actuating unit. The unit is detachably related to the thrust transmitting structure so that the aforesaid actuating units can be readily interchanged or replaced as desired without disassembly of the thrust transmitting structure, With this arrangement, two separate and complete types of m'echanism are unnecessary for breake'rs than-can be operated manually as well as by motor or solenoid since a single mechanism can assume either type and be; efliciently operated by either a manual or electromagnetic actuating unit.

. Our invention will be more fully set forth in the following description referring to the accompanying drawing, and the features of novelty which characterize our invention will be pointed outwith particularity in the claims annexed to and. forming a part of this specification.

Referring to the drawing, Fig. 1 is a perspective view, partly in section and partly diagrammatic of an electric circuit breaker mechanism of the interchangeable manual operating type embodying the present invention, Fig. 2 is a side elevational view of the assembled mechanism unit of Fig. 1. Fig. 3; is a similar view of the mechanism with a solenoid actuating unit, and Fig. 4 is another view of the mechanism with a motor actuating unit.

The complete operating mechanism illustrated by way of example comprises an interchangeable actuating unit generally indicated at I, a main operating toggle 2, and a tripping device for the toggle mechanism generally indicated at 3. The'electric circuit breaker to be operated is shown .atAz Certain features. of this mechanism: are disclosed and claimed in Patent No. 2,152,453 issued March 28, 1939, to Atwood and Rudolph for Operating mechanism, and assigned to the same assignee as the present invention.

The actuating unit I, which is shown in Fig. 1 as of the manual type, comprises a reciprocally guided plunger or crosshead .5. that is connected through a link 5 and crank 1 to a manual operating handle 6. .The manual handle 6 is rotatablym'ounted in the front wall of the casing of the manualiunit M (Fig. 2), the handle shaft including an extension 6 or rectangular crosssection slidably guided in' the circular crank arm 1 The crank '1 is operatively connected to the link 5' through the horizontal crank arm I. The link 5' and the crosshead Eare detachably interconnected as by a removable pin 2' so that the manual handle and crank can be removed without disassembly of thelinkage Z.

A spring 8 seated at oneend on a shoulder of the shaft 6' and at the opposite end at the inner wall of the unit M tends to bias th handle 6 toward-said unit. A tripping detent 8' secured to thelshaft 6' .causes'tripping of the linkage 2 in a manner presently describedwhen the handle 6 is drawn outwardly against the spring}.

Referring .;more particularly to the thrust crosshead \for a purpose hereinafter described.

The link I I is connected to a guide link I3 having a fixed pivot at I4, and the link I2 to a crank I5 that is rotatable on a shaft I6.

generally U-shaped member havingsubstantially parallel sides I5 through which the shaft I5 e e tends, interconnected by an integral transverse strip I5" extending parallel to the shaft. The crank at one side is provided with a cam surface il adapted to coact with a circuit breaker crank I8 which is rigidly connected through a rotatable countershaft I9 to, th movable arm 2 f the circuit breaker -4.--When the crank I is rotated clockwise as viewed by straightening of the main toggle I I-l 2 in response to elevation of the crosshead 5, the cam face II bearing on the roller I8 of the breaker crank rotates the breaker shaft I9 in counterclockwise direction whereby the movablecontact structure 20 of the circuit breaker 4 is moved into contact engagement with the stationary contact structure 2 I This movement, or working stroke of the breaker structure 20 is generally in opposition to spring pressure tending to bias the breaker to open circuit position.

" For the purpose of holding the toggle I I-I2 at the pivot I3 in thrust-transmitting position with respect to the crank I5 the toggle guide link I3 is related to suitable latching and tripping means comprising a link 22 connected to the toggle pivot I3and to a latch 23 having afixed pivot at 24. The members 22 and 23 are suitably interconnected as at 25 for insuring a force-reducing connection. Coacting with the latch 23 is a rotatable trippingshaft 28 to-which is secured a detent member 21 adapted to engage the latch 23 at the notched p0rtion28.

'In" the position showncollapse of the toggle 'I II2, that is," counterclockwise rotation ofthe toggle pivot I3 and dropping of the knee joint, is restrained by thelatch 23 and detent 21. Tr pping movement, that is, counterclockwise rotation of the tripping shaft 26, effects release of the latch 23 so that it is free to rotate counterclockwise for releasing the pivot I3" and permitting opening movement or collapse of the toggle.

In the closed circuit or restraining position shownthe tripping means '3 is latched and the toggle is held in an underset extended position by a prop 29 adapted to support the knee ID of the toggle. The prop is shown as belng secured to a rotatable shaft 30 that is resiliently connected by a spring 3I, as illustrated, to th tripping shaft 26 so as to facilitate resetting ofboth the prop and the latching means after a circuit opening or releasing operation of the mechanism.

Referring more particularly to the tripping means, the tripping shaft 26 is provided with an offsetportion or arm 32 for coacting with a tripping means 33- that is shown as a solenoid energized from a control source through a switch 34.

I The member 32 may also be engaged by manual tripping means indicated at 32'. Manual tripping by the handle Ii may also be provided as previously' indicated. When the breaker .is closed as shown in Fig. '1 and the handle 6 is in the lower position, tripping is accomplished by drawing the Th crank I5, which is operated by the toggle 2 in response to operation of the actuatingi unit,

such as by rotation of the handle 6, comprises a. l

handle outwardly against the spring 8. During this operation, the detent 8 rotates the member 40 about its axis at M by engaging the alined lug 42. The tripping shaft 25 is thereupon rotated to trip the mechanism through a member 43 arranged to tilt a projection 43 secured to said shaft. The conventionaloverload tripping V coil 35 shown as energized from the main circuit at 4' also coacts with the tripping shaft at 36, operation of any of the above described tripping means causing counterclockwise rotation of the tripping shaft and release of the main toggle.

The breaker crank I8 is also connected to the crank I5 by means of a compression spring 31 guided'on a member 38 engaging one end of the crank I5 and having a guided sliding connection at 39 with an arm of the crank I8. In the closed circuit position shown the spring 31 is under compression so that immediately upon release of the tripping latch, opening movement of the toggle II-.-I2 is accelerated. by.the stored spring energy, resulting inrapid' movement of the cam surface I! away from theroller I8. 7 The circuit breaker crank. I8 .is also acted upon throughout thevbreaker:opening stroke by the spring 3! tending to accelerate separation of the contactsZil and 2 I During the closingloperation when the crank I5. i rotated clockwise :thespring 3'! is placed under compression by reason of the comparatively long lever arm of the crank I8,acting in the opposite direction on thespring.

When the toggle I'I-l2 is released in response to a tripping operation, the toggle pivot [3' is free to rotate counterclockwise, about, pivot I.4 thereby causing shifting ;of: the toggle knee I 9 from the end .of the'prop 29 .and per i opening movement of: the toggle. In the case ;of manual operation, complete collapse of the toggle and resetting. of the mechanism is deferred until the handle 6 is rotated toward the reset position. When this occurs, the pivot I3'-re verses its movement and drops so that the latch 23 can return to its initial position during which return movement itrides over the latch detent 21 and resets in the position illustrated, 1',I'he prop 29 is suitably shaped, as illustrated, for permitting free movement of the toggle knee LII alongside theprop. l l V The, resilient connection 3I between the trip shaft 273 and the prop shaft 3fl biases the tripping detent into latching engagement after the latch 23 indropping pushes down on and passes by the latoh d fi t2 11 6 a er s pp n int reset pos n ettqtheb i f. s r 31- :At

thesame time thespring3l exerts a counter clockwise bias on the prop 23 urging it against the side of linkfi sothat when'the'links II and I2 are raised to toggle. position v in a subseguent closing operation, the prop 29 is snapped beneath the toggle knee; Hi to holdthe mechanisrn in closed position independently of the actuating means. A stop member 29' is provided for prelventing movement of the propbeyond the toggle nee. 1

It will therefore be noted that the mechanism is trip-free in operation since at any time-during the closing stroke, release of the toggle pivot I3 in response to a tripping operation causes freeing of the toggle and opening of the circuit breaker.' The opening speed is very rapid due to the fact that the main toggle can simply shift laterally offthe prop 29 to open th breaker, sincev completecollapse ofthe toggle is not re breakin iiqf. the :toeele :is; ere or un e s ry to initiate the opening movement. In the case of trip-free operation asthe crosshead is elevated by rotation of the handle B as indicated at close, the toggle remains inthe extended position shown during the-opening stroke. The resetting operation then depends on lowering of the crossheadby the handleas indicated at resetin order that the latch 23 may drop to its latching position. This resetting operation is also followed for normal tripping. The circuit breaker can, if desired, have separate means such as springs for normally biasing the same toward open circuit position.

. The mechanism proper above described, apart from the manual actuating unit, is permanently mounted in a frame 44 as shown by Figs. 2 and 3 comprising a pair of side plates suitably secured to a support or panel 45. The various shafts and pivots of the mechanism can be journalled in the side plates, as indicated, so that the mechanism proper is a compact and integral unit.

Referring now to the actuating units, the

manual unit M comprises a compact casing or housing 46 having depending side walls and open at its lower end. The manual handle 6 is rotatably mounted in the front wall, as shown, and the crank 1 and the associated connections for the crosshead 5 are enclosed by the casing. The crosshead 5 is guided at 41 by the extensions of the laterally disposed pin 9' for vertical reciprocal movement in slots in the frame side walls extending from the upper edges thereof. The manual unit casing is designed to fit between the frame side walls as shown and to be detachably mounted, as by screws 48, to the frame so as to enclose the upper part of the mechanism. Accordingly when it is desired to interchange or replace the unit M, the screws 48 are simply removed, the pin 2' at the crosshead withdrawn, and the unit simply lifted from the frame.

Where a solenoid unit S, as indicated in-Fig. 3, is preferred, the unit is simply inserted in the frame 44 in the manner above described and the screws 48- secured in position after the solenoid plunger or armature, which nowserves as the crosshead 5, is operatively connected to the link 9. For simplifying the arrangement when changing from manual to solenoid operation, the pin 2 at the crosshead can be withdrawn as above described, after which the crosshead 5 is removed. The links 9 are then connected directly by the pin to the solenoid armature which is guided in the frame at 41 as illustrated. The mechanism then can function as a conventional complete solenoid device without further alteration.

Fig. 4 illustrates the application of another form of electromagnetic operating device, namely an electric motor unit generally indicated at E, to the above described mechanism. As illustrated, the electric motor unit E comprises a unitary structure that is secured, as in the case of the solenoid unit, at 48 to the mechanism frame 44. The motor unit includes a self-contained brake and cam operator, the specific details of which form no part of the present invention and are omitted in the interest of clearness. By way of example, the motor and brake structure can be of the character disclosed and claimed in Patent No. 2,034,145, granted March 17, 1936 to L. J. Linde for Operating mechanism.

Referring more particularly to Fig. 4, the motor unit includes an electric motor 50, the

automatic brake indicated at 56.

in the manner above described.

rotor shaft 5| of which is vertically positioned and provided with a worm drive 52 for coasting with a worm gear 53 that is secured. to. the cam shaft 54. The cam 55, which is mounted onthe 'shaft54 is of suitable design and is actuated in'clo'ckwise direction upon energization of the motor 50. The cam and its associated shaft and operating gears, together with the self-contained brake unit indicated at 56, are suitably mounted ona unitarysupport 5 that is in turnsecured as at 58 to the motorhousing 50.

In a motoroperated cam mechanism of the character above described, the motor is. energizedfor predetermined rotation of. theicam, after which the motor is deenergized and the rotating parts brought to a quick stop bythe The camfollower, which generally comprises a roller or the like is suitably connected to the means to' be operated, which in the present case comprises the crosshead 5 shown by Fig. 1. As illustrated,

the crosshead 5 at 66 isconnected to the cam follower or roller 59- through a link 6!]. that is slotted as indicated at 6| to receive cam shaft 54. Accordingly the link 60 is guided for reciprocal rectilinear movement both by the cam shaft and by the=guided crosshead 5soithat the cam follower is limited to reciprocal rectilinear movement. 2

The operation of the mechanism when used in connection with the motor .unit E is essentially the sameas that previously described. That is, rotation of the cam 55 in clockw'ise direction causes elevation ofxthe crosshead 5 and closing of the breaker. When the mechanism is to be reset, the cam is simply-rotated beyond its high point so that the cam follower drops to the low point, thereby permitting collapse of the toggle and resetting of the mechanism It should be particularly noted that formotor, manual and solenoid operation the mechanism in the case of each is rugged and compact and symmetrical with respect to the actuating force. This is equivalent to three separate operating mechanism designs, each of which is highly efficient and particularly adapted to the particu-- lar operating problems in question. By avoiding unnecessary and complicated operating linkage and associated structure, the actuating force can be more effectively and eificiently applied, thereby securing a more compact and efficient design for a given power rating.

It should be understood that our invention is not limited to specific details of constructionv and arrangement thereof herein illustrated, and that changes and modifications may occur to one skilled in the art without departing from the spirit of our invention.

What we claim as new and desire to secure by Letters Patent in the United States is:

1. Circuit breaker operating mechanism comprising a supporting frame including a pair of spaced plate-like side members, thrust transmitting linkage mounted in said frame between said plate members, a member guided for reciprocal movement between said plate members for actuating said linkage, said frame .at its topportion being adapted to receive in interchangeable relation an actuating unit for reciprocating said member, means for detachably mounting said unit in said frame so that it can be lifted and replaced or interchanged independently of said thrust transmitting linkage, and means for directly connecting said unit to said guide mem- .ber withoutremoval of. said member from said l-frame; i V

' 2. Circuit breaker operating mechanism comprising. a supporting frame, thrust transmitting ,linkagemounted in said frame, a member guided for reciprocal movement in said frame for ac,- tuating said linkage, said frame at its top portion being recessed to receive in interchangeable relation electromagnetic and manual actuating units, means, for detachably mounting the actuating unit in said, frame so that it can be readilylifted from or inserted therein, and means for detachably relating said'unit to said guide (member whereby the actuating unit can be replaced or interchanged without disassembly or ,removal of said thrust transmitting linkage.

J 3.Circuit breaker operating mechanism comprising a supporting frame including spaced plate-like side members, thrust transmitting :linkagemounted in said frame, acrosshead member guided for longitudinal reciprocal movement between said plate members for actuating said linkage, the plate-like sides of said frame at the top portion being adapted to receive in detachable and interchangeable relation an actuating unit of electromagneticor manual type so that said unit can be readily lifted from or seated on said platev members, and means for operatively relating said unit to said crosshead member whereby replacement or substitution of said unit can be effected without disassembly or removal of said thrust transmitting linkage.

34. Circuit breaker operating mechanism comprising a supporting frame, thrust transmitting linkage mounted in said frame, a member guided for reciprocal'movement in said frame for actuating said linkage, an actuating unit adapt prising a supporting frame having spacedplatelike sides, thrust transmitting linkage including a toggle mounted in said frame between said plates, said frame at its top portion being adapted to receive in'detachable interchangeable relation an actuating unit of the electromagnetic or manual types so that said unit can be readily lifted from or seated on said frame, a member connected to the knee of said toggle for operating the same in rectilinear movement, said member being guided in vertical slots in said plates, and meansfor operatively relatingsaid member to said unit whereby said unit can be replaced or interchanged without disassembly or removal of said toggle.

6. In an operating mechanism for an electric switch having a movable circuitcontrolling member, toggle actuating means for moving said circuit-controlling member to the circuit-closing position means for maintaining said toggle actuating means in a position to hold said circuit; controlling member in the circuit-closing position, and a rotatably mounted operating member arranged for translatory movement operable upon translatory movement in one directionto release said toggle actuating means from the holding position and rotatable in one direction to reset said toggle actuating means and in the opposite direction to effect the movement of said circuit-controlling member to the circuit-closing position.

'7. In an operating mechanism for an electric switch having a movable circuit-controlling member, toggle actuating means for moving said member to a predetermined circuit-closin position, means for maintaining said toggle actuating means in .a position to hold said member in said circuit-controlling position, and a rotatably mounted operating member arranged for translatory movement operable upon translatory movement in one direction to release said toggle actuating means fromthe holding position and rotatable in one direction to reset said toggle actuating means and in the opposite direction to effect the movement of said circuit-controlling member to said circuit-controlling position.

WINFIELD A. A'I'WOOD. JOSEPH W. SEAMAN. 

